Plastic cell and method for manufacturing same

ABSTRACT

An object of the present invention is to provide a plastic cell that maintains conductivity without losing a sealing property and allows extension of an electrode even in a case where a plastic substrate is deformed into a free shape with roughness or curved surfaces, and a method for manufacturing the same. The plastic cell of the present invention includes a first plastic substrate, a first transparent conductive layer, a fluid layer, a second transparent conductive layer, and a second plastic substrate, in this order, the plastic cell further including a sealing part that seals the fluid layer by deformation of a part of the first plastic substrate or the second plastic substrate, in which the first plastic substrate has a first through-hole, the second plastic substrate has a second through-hole, the first through-hole has a first conductive material therein, and the second through-hole has a second conductive material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of PCT International Application No.PCT/JP2017/005820 filed on Feb. 17, 2017, which claims priority under 35U.S.C. § 119(a) to Japanese Patent Application No. 2016-030065 filed onFeb. 19, 2016. The above application is hereby expressly incorporated byreference, in its entirety, into the present application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a plastic cell using a plasticsubstrate and a method for manufacturing the same.

2. Description of the Related Art

In recent years, liquid crystal display devices have evolved intovarious forms, and flexible displays which are light-weight and bendablehave attracted attention. In liquid crystal cells used for such flexibledisplays, it is difficult to meet the requirements of being light-weightand bendable with a glass substrate which has been used in the relatedart. Thus, various types of plastic substrates have been studied as asubstitute for the glass substrate.

Further, applications of a liquid crystal cell have spread to lightcontrol devices used for applications such as packaging, decoration,interior design, building materials, and vehicles. Also in such lightcontrol devices, it is desirable to use a liquid crystal cell which islight, has flexibility of being bendable, and further has a free shapewith roughness and curved surfaces rather than a two-dimensional plane.Even in substrates for these applications, there is a need for practicaluse of a plastic substrate as a substitute for the glass substrate.

On the other hand, in a case of manufacturing a liquid crystal cellhaving flexibility, it is necessary that a sealing agent for sealing aliquid crystal compound in the liquid crystal cell also has flexibility.

As a sealing agent having such flexibility, for example, JP1987-18523A(JP-562-18523A) discloses a sealing agent using an epoxy resin curedproduct to which flexibility has been imparted.

Further, JP1987-70814A (JP-S62-70814A) discloses a sealing method ofperforming a direct thermal fusion welding of flexible supports to eachother, which makes it possible to withstand bending.

SUMMARY OF THE INVENTION

The present inventors studied the sealing agent described inJP1987-18523A (JP-S62-18523A) and a method of reinforcing a sealing partby thermal fusion welding described in JP1987-70814A (JP-S62-70814A). Asa result, it is found that in a case where a plastic substrate having aroughness shape or a curved surface shape is used, there are some caseswhere a sealing property is lost and it is difficult to drive a liquidcrystal, that is, to maintain conductivity thereof. In addition, in thereinforcing method described in JP1987-70814A (JP-S62-70814A), forextension of a lead wire portion (electrode), all sides of a cell cannotbe subjected to a thermal fusion welding, and there is a need forcombined use of performing a thermal fusion welding for two sidesthereof and using a sealing agent for the remaining two sides.

Accordingly, an object of the present invention is to provide a plasticcell that maintains conductivity without losing a sealing property andallows extension of an electrode even in a case where a plasticsubstrate is deformed into a free shape with roughness or curvedsurfaces, and a method for manufacturing the same.

As a result of intensive studies, the present inventors have found that,with respect to a sealing method used for a plastic cell, even in a casewhere a plastic substrate is greatly deformed by deforming (for example,performing a thermal fusion welding of) a part of plastic substratesdisposed above and below the plastic cell to seal a fluid layer and byproviding through-holes in the plastic substrates and filling them withconductive materials, conductivity of the plastic cell can be maintainedwithout losing a sealing property and extension of an electrode isallowed.

That is, it has been found that the object can be achieved by thefollowing configuration.

[1] A plastic cell comprising:

-   -   a first plastic substrate, a first transparent conductive layer,        a fluid layer, a second transparent conductive layer, and a        second plastic substrate, in this order,    -   in which the plastic cell further comprises a sealing part that        seals the fluid layer by deformation of a part of the first        plastic substrate or the second plastic substrate,    -   the first plastic substrate has a first through-hole,    -   the second plastic substrate has a second through-hole,    -   the first through-hole has a first conductive material therein,        and    -   the second through-hole has a second conductive material        therein.

[2] The plastic cell according to [1],

-   -   in which the first conductive material is the same material as        the first transparent conductive layer, and the second        conductive material is the same material as the second        transparent conductive layer.

[3] The plastic cell according to [1] or [2],

-   -   in which an orientation layer is provided between the first        transparent conductive layer and the fluid layer and between the        second transparent conductive layer and the fluid layer,        respectively, and    -   the fluid layer is a liquid crystal layer formed by using a        liquid crystal composition containing a liquid crystal compound.

[4] The plastic cell according to any one of [1] to [3],

-   -   in which both the first plastic substrate and the second plastic        substrate are elongated films, and    -   the plastic cell is in a roll form obtained by winding the        elongated films in a longitudinal direction.

[5] The plastic cell according to any one of [1] to [4], furthercomprising an electrode,

-   -   in which the electrode is connected to at least one of the first        transparent conductive layer or the second transparent        conductive layer via the conductive material.

[6] A method for manufacturing a plastic cell, comprising:

-   -   a step of forming a first through-hole in a first elongated        plastic substrate,    -   a step of disposing a first transparent conductive layer on the        first elongated plastic substrate having the first through-hole        formed therein;    -   a step of forming a second through-hole in a second elongated        plastic substrate,    -   a step of disposing a second transparent conductive layer on the        second elongated plastic substrate having the second        through-hole formed therein;    -   a step of disposing a fluid layer on the first transparent        conductive layer;    -   a step of bonding the first plastic substrate, in which the        fluid layer is disposed on the first transparent conductive        layer, and the second plastic substrate, on which the second        transparent conductive layer is disposed, to each other by a        roll-to-roll process, to produce an elongated laminate;    -   subsequent to production of the laminate, a step of performing a        thermal fusion welding of the first plastic substrate and the        second plastic substrate to each other, to seal the fluid layer        in the longitudinal direction; and    -   a step of winding the laminate in a roll shape.

According to the present invention, it is possible to provide a plasticcell that maintains conductivity without losing a sealing property evenin a case where the plastic substrate is deformed into a free shape withroughness or curved surfaces, and a method for manufacturing the same.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view showing one embodiment of aplastic cell of the present invention.

FIG. 2 is a schematic cross-sectional view showing one embodiment of theplastic cell of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described in detail.

Descriptions of constituent elements described below are made based onrepresentative embodiments of the present invention, but the presentinvention is not limited to such embodiments.

In the present specification, a numerical range expressed using “to”means a range including numerical values described before and after thepreposition “to” as a lower limit value and an upper limit value.

Further, in the present specification, “cutting” includes “punching”,“slicing”, and the like.

[Plastic Cell]

The plastic cell of the present invention includes a first plasticsubstrate, a first transparent conductive layer, a fluid layer, a secondtransparent conductive layer, and a second plastic substrate, in thisorder.

Further, the plastic cell of the present invention includes a sealingpart that seals the fluid layer by deformation of a part of the firstplastic substrate or the second plastic substrate.

Furthermore, in the plastic cell of the present invention, the firstplastic substrate and the second plastic substrate have a firstthrough-hole and a second through-hole, respectively.

Furthermore, in the plastic cell of the present invention, the firstthrough hole and the second through hole have a first conductivematerial and a second conductive material therein, respectively.

Each of FIGS. 1 and 2 is a schematic cross-sectional view showing oneembodiment of a plastic cell of the present invention.

As shown in FIGS. 1 and 2, the plastic cell 100 of the present inventionincludes a first plastic substrate 1, a first transparent conductivelayer 2, a fluid layer 4, a second transparent conductive layer 6, and asecond plastic substrate 7, in this order. In the embodiments as shownin FIGS. 1 and 2, an orientation layer 3 and an orientation layer 5 aredisposed between the first transparent conductive layer 2 and the fluidlayer 4 and between the second transparent conductive layer 6 and thefluid layer 4, respectively.

Further, as shown in FIGS. 1 and 2, the plastic cell 100 of the presentinvention includes a sealing part 14 that seals the fluid layer 4 bydeformation of a part of the first plastic substrate 1 or the secondplastic substrate 7.

Further, as shown in FIG. 2, in the plastic cell 100 of the presentinvention, the first plastic substrate 1 has a first through-hole 12 andthe second plastic substrate 7 has a second through-hole 13. The firstthrough-hole 12 has a first conductive material therein and the secondthrough-hole 13 has a second conductive material therein.

In the embodiment as shown in FIG. 2, the first conductive material andthe second conductive material are formed integrally with thetransparent conductive layer 2 and the transparent conductive layer 6,respectively. In addition, in the embodiment as shown in FIG. 2, aconductive paste 9 and a conductive paste 11 are provided on theconductive materials in the through-hole 12 and the through-hole 13,respectively, and these pastes are connected to electrodes (not shown)via conductive wires 8 and 10 which connect to the electrodes.

[Plastic Substrate]

Both the first plastic substrate and the second plastic substrate(hereinafter abbreviated as “plastic substrate” in a case wheredistinction is not particularly required) of the plastic cell of thepresent invention are a substrate used from the viewpoint of achieving ahigh degree of freedom in moldability.

In a case of manufacturing a plastic cell, since dimensional changessuch as stretching and shrinkage occur locally, it is preferable to usea thermoplastic resin as the plastic substrate.

As the thermoplastic resin, a polymer resin which is excellent inoptical transparency, mechanical strength, thermal stability, and thelike is preferable.

Examples of the polymer included in the thermoplastic resin includepolycarbonate-based polymers; polyester-based polymers such aspolyethylene terephthalate (PET); acrylic polymers such as polymethylmethacrylate (PMMA); styrene-based polymers such as polystyrene andacrylonitrile-styrene copolymers (AS resins); and the like.

Further, polyolefins such as polyethylene and polypropylene;polyolefin-based polymers such as norbornene-based resins andethylene-propylene copolymers; vinyl chloride-based polymers;amide-based polymers such as nylon and aromatic polyamide; imide-basedpolymers; sulfone-based polymers; polyether sulfone-based polymers;polyether ether ketone-based polymers; polyphenylene sulfide-basedpolymers; vinylidene chloride-based polymers; vinyl alcohol-basedpolymers; vinyl butyral-based polymers; arylate-based polymers;polyoxymethylene-based polymers; epoxy-based polymers; cellulosicpolymers typified by triacetyl cellulose; copolymers copolymerized withmonomer units of these polymers; or the like can be mentioned.

Further, examples of the thermoplastic resin include polymers obtainedby mixing two or more of the polymers exemplified above.

{Through-Hole}

The plastic substrate of the plastic cell of the present invention has athrough-hole.

Here, a shape of the through-hole is not particularly limited, and itmay be various shapes such as a circle and a rectangle.

{Conductive Material}

The through-hole of the plastic substrate has a conductive material inthe through-hole.

A material used for the conductive material is not particularly limited;and it is preferable to use the same material as the material used forthe transparent conductive layer as described later, and it is morepreferable that the material is formed integrally with the transparentconductive layer as described later. In this case, by forming thethrough-hole in the plastic substrate and then disposing the transparentconductive layer, the transparent conductive layer can be continuouslyformed even into the through-hole so as to also serve as a conductivematerial.

The conductive material preferably occupies 50% or more of a volume ofthe through-hole, more preferably occupies 70% or more thereof, andstill more preferably 90% or more thereof.

[Transparent Conductive Layer]

Both the first transparent conductive layer and the second transparentconductive layer (hereinafter abbreviated as “transparent conductivelayer” in a case where distinction is not particularly required) of theplastic cell of the present invention are a layer having conductivityand disposed on the plastic substrate.

In the present invention, “having conductivity” means that a sheetresistance value is 0.1 Ω/square to 10,000 Ω/square, and generally alsoincludes those called an electric resistance layer.

Further, in a case of being used as an electrode of a flexible displaydevice or the like, the sheet resistance value is preferably low;specifically, it is preferably 300 Ω/square or less, particularlypreferably 200 Ω/square or less, and most preferably 100 Ω/square orless.

In the transparent conductive layer used in the present invention,“transparent” means that a transmittance is 60% or more and 99% or less.

The transmittance of the transparent conductive layer is preferably 75%or more, particularly preferably 80% or more, and most preferably 90% ormore.

As materials that can be used for the transparent conductive layer usedin the present invention, metal oxides (Indium Tin Oxide: ITO and thelike), carbon nanotubes (Carbon Nanotube: CNT, Carbon Nanobud: CNB, andthe like), graphene, polymer conductors (polyacetylene, polypyrrole,polyphenol, polyaniline, PEDOT/PSS, and the like), metal nanowires(silver nanowires, copper nanowires, and the like), metal mesh (silvermesh, copper mesh, and the like), and the like can be used.

Here, “PEDOT/PSS” means a polymer complex in which PEDOT (polymer of3,4-ethylenedioxythiophene) and PSS (polymer of styrene sulfonic acid)coexist.

Further, a conductive layer of the metal mesh is preferably formed bydispersing conductive fine particles of silver, copper, or the like in amatrix rather than being formed only of a metal.

A metal oxide such as ITO is a ceramic material and has a problem thatcracks are easily formed by a stretching action to remarkably increasethe sheet resistance value in a case of being molded without utilizingshrinkage as in technologies of the related art. On the other hand, inthe present invention, generation of cracks can be suppressed byutilizing shrinkage, and the problem of exhibiting a high sheetresistance value, which has been a problem in the related art, can beimproved so that such material can be used as a transparent conductivelayer.

A conductive layer in which particles such as metal mesh form, carbonnanotube form or metal nanowires are dispersed in a matrix can easilyfollow shrinkage of the plastic substrate by making a glass transitiontemperature (Tg) of the matrix equal to or lower than a shrinkagetemperature of the plastic substrate and is preferable because suchconductive layer can suppress generation of wrinkles and suppressincrease of haze as compared with a conductive layer using a metal oxideand a polymer conductor.

[Orientation Layer]

In the plastic cell of the present invention, an orientation layer maybe comprised between the transparent conductive layer provided on theplastic substrate and the fluid layer described later. In a preferredembodiment, the orientation layer is provided on the uppermost surfaceof each of the first plastic substrate and the second plastic substrateused for the plastic cell, and allows the plastic cell to have afunction of orientating the fluid layer containing a liquid crystalcompound.

In a case where no voltage is applied, the orientation layer used in thepresent invention may be an orientation layer for horizontallyorientating the liquid crystal compound contained in the fluid layer oran orientation layer for vertically orientating the same.

Materials for the orientation layer and treatment methods thereof arenot particularly limited, and it is possible to use various orientationlayers such as an orientation layer using a polymer, an orientationlayer obtained by being subjected to a silane coupling treatment, anorientation layer using a quaternary ammonium salt, an orientation layerobtained by depositing silicon oxide from an oblique direction, and anorientation layer utilizing photoisomerization. In addition, as asurface treatment for the orientation layer, a surface treatmentperformed by rubbing treatment, energy ray irradiation,photo-irradiation, or the like may be used.

The orientation layer using a polymer preferably includes any one of alayer using a polyamic acid or a polyimide; a layer using a modified orunmodified polyvinyl alcohol; a layer using a modified or unmodifiedpolyacrylic acid; or a layer using a (meth)acrylic acid copolymercontaining any one of a repeating unit represented by General Formula(I), a repeating unit represented by General Formula (II), or arepeating unit represented by General Formula (III).

Further, “(meth)acrylic acid” is a description representing acrylic acidor methacrylic acid.

In General Formulas (I) to (III), R¹ and R² each independently representa hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbonatoms; M represents a proton, an alkali metal ion, or an ammonium ion;L° is a divalent linking group selected from the group consisting of—O—, —CO—, —NH—, —SO₂—, an alkylene group, an alkenylene group, anarylene group, and a combination thereof; R⁰ is a hydrocarbon grouphaving 10 to 100 carbon atoms or a fluorine atom-substituted hydrocarbongroup having 1 to 100 carbon atoms; Cy is an alicyclic group, aromaticgroup, or heterocyclic group, particularly preferably, having acarbazole group; m is 10 to 99 mol %; and n is 1 to 90 mol %.

Among these, it is preferable to use an orientation layer containing anyone of polyimide, compounds represented by General Formulas (I) to(III), and a silane coupling agent from the viewpoints of orientationcapability, durability, insulation property, and costs; and it isparticularly preferable to use an orientation layer containing any oneof polyimide or compounds represented by General Formulas (I) to (III)and having a carbazole group.

Further, as the orientation layer, a photo-orientation layer capable oforientating a liquid crystal by irradiation with polarized andunpolarized ultraviolet (UV) light may be used.

[Fluid Layer]

The fluid layer of the plastic cell of the present invention is notparticularly limited as long as it is a continuous body having fluidityother than gas and plasma fluid.

As a particularly preferred substance state, a liquid and a liquidcrystal are preferable, and as the fluid layer, a liquid crystal layerformed by using a liquid crystal composition containing a liquid crystalcompound is most preferable.

Here, in general, the liquid crystal compound can be classified into arod-like type and a disk-like type depending on its shape. These typesfurther have a low molecule type and a high molecule type, respectively.The high molecule generally refers to one having a degree ofpolymerization of 100 or more (Polymer Physics-Phase TransitionDynamics, by Masao Doi, p. 2, published by Iwanami Shoten, Publishers,1992). In the present invention, any liquid crystal compound can beused. However, it is preferable to use a rod-like liquid crystalcompound or a discotic liquid crystal compound (disk-like liquid crystalcompound). Two or more rod-like liquid crystal compounds, two or moredisk-like liquid crystal compounds, or a mixture of the rod-like liquidcrystal compound and the disk-like liquid crystal compound may be used.In order to immobilize the above-described liquid crystal compound, itis more preferable to use a rod-like liquid crystal compound ordisk-like liquid crystal compound having a polymerizable group to formthe liquid crystal compound, and the liquid crystal compound still morepreferably has two or more polymerizable groups in one molecule. In acase of using a mixture of two or more liquid crystal compounds, it ispreferable that at least one liquid crystal compound has two or morepolymerizable groups in one molecule.

The plastic cell of the present invention is preferably an embodiment inwhich the above-described fluid layer is a liquid crystal layer, thatis, a liquid crystal cell.

Here, the liquid crystal cell means a liquid crystal cell used forliquid crystal display devices used for a thin television, a monitor, anotebook computer, a cellular phone, and the like, and a liquid crystalcell used for light control devices for changing intensity of lightwhich is applied to interior design, building materials, vehicles, andthe like. That is, the liquid crystal cell is a general term for devicesthat adjust a voltage to drive a liquid crystal composition having apolarizability such as a liquid crystal composition sealed between twosubstrates.

As a driving mode of the liquid crystal cell, various methods includingin-plane-switching (IPS), vertical alignment (VA), twisted nematic (TN),and super twisted nematic (STN) can be used.

Further, inside the cell in the plastic cell of the present invention,colorant molecules and the like used for changing intensity of light ina light control element may be used in combination.

Further, depending on a configuration of the liquid crystal cell, abacklight member, a polarizing plate member, a member for controllingsurface reflection, and the like may be used outside the liquid crystalcell by juxtaposition or bonding.

[Sealing Part]

The plastic cell of the present invention has a sealing part for sealingthe above-described fluid layer.

Here, since the sealing part is formed by deformation of a part of thefirst plastic substrate or the second plastic substrate, it includes apart of the first plastic substrate or the second plastic substrate.

Further, it is preferable that the sealing part is a seal formed byperforming a thermal fusion welding of plastic substrates to each other.

In the plastic cell of the present invention, a planar shape may be arectangular shape. The rectangular shape may be a square or an oblong,and there is no limitation on a size.

Further, in the plastic cell of the present invention, the planar shapemay be a shape other than a rectangle. For example, the planar shape maybe a circle, an ellipse, a triangle, a pentagon or higher polygon, or afree shape obtained by combination of a straight line and a curved line,or may be a shape that is hollow on the inside like a donut shape in acase where a periphery of the plastic cell is sealed.

Furthermore, in the plastic cell of the present invention, an elongatedfilm can be used as the first plastic substrate and second plasticsubstrate. Thus, it is also possible to form the plastic cell and thenwind it in a longitudinal direction into a roll form. This cancontribute to packing, shipping, transportation, and the like of theplastic cell of the present invention.

[Electrode]

In the plastic cell of the present invention, in order to apply adriving voltage, an electrode connected to the transparent conductivelayer may be installed via a conductive material. For example, a methodin which, for a conductive material exposed on a surface at a sideopposite to the transparent conductive layer of the plastic substrate, aconductive material such as a silver paste, a conductive tape, or thelike is used to connect to a lead terminal, or the like can be used.

[Method for Manufacturing Plastic Cell]

The method for manufacturing a plastic cell of the present invention(hereinafter also abbreviated as “manufacturing method of the presentinvention”) is a method for manufacturing the plastic cell, including:

-   -   a step of forming a first through-hole in a first elongated        plastic substrate (hereinafter also abbreviated as “through-hole        forming step 1”);    -   a step of disposing a first transparent conductive layer on the        first elongated plastic substrate having the first through-hole        formed therein (hereinafter also abbreviated as “conductive        layer disposing step 1”);    -   a step of forming a second through-hole in a second elongated        plastic substrate (hereinafter also abbreviated as “through-hole        forming step 2”);    -   a step of disposing a second transparent conductive layer on the        second elongated plastic substrate having the second        through-hole formed therein (hereinafter also abbreviated as        “conductive layer disposing step 2”);    -   a step of disposing a fluid layer on the first transparent        conductive layer (hereinafter also abbreviated as “fluid layer        disposing step”);    -   a step of bonding the first plastic substrate, in which the        fluid layer is disposed on the first transparent conductive        layer, and the second plastic substrate, on which the second        transparent conductive layer is disposed, to each other by a        roll-to-roll process, to produce an elongated laminate        (hereinafter also abbreviated as “laminate producing step”);    -   subsequent to production of the laminate, a step of performing a        thermal fusion welding of the first plastic substrate and the        second plastic substrate to each other, to seal the fluid layer        in the longitudinal direction (hereinafter also abbreviated as        “sealing step”); and    -   a step of winding the laminate in a roll shape.

Hereinafter, the through-hole forming step 1 and the through-holeforming step 2 (hereinafter, abbreviated as “through-hole forming step”in a case where distinction is not particularly required), theconductive layer disposing step 1 and the conductive layer disposingstep 2 (hereinafter, abbreviated as “conductive layer disposing step” ina case where distinction is not particularly required), and the fluidlayer disposing step, the laminate producing step, and the sealing stepwill be described in detail.

[Through-Hole Forming Step]

In the manufacturing method of the present invention, the through-holeforming step is a step of forming a first through-hole in a firstelongated plastic substrate, and the through-hole forming step 2 is astep of forming a second through-hole in a second elongated plasticsubstrate.

Here, a method of forming the through-hole in the plastic substrate isnot particularly limited, and various known methods can be used. Forexample, the through-hole can be formed by using frog-shaped pin,needle, drill, laser such as carbon dioxide gas laser or yttriumaluminum garnet (YAG) laser, plasma, or the like.

[Conductive Layer Disposing Step]

In the manufacturing method of the present invention, the conductivelayer disposing step 1 is a step of disposing the first transparentconductive layer on the first elongated plastic substrate having thefirst through-hole formed therein, and the conductive layer disposingstep 2 is a step of disposing the second transparent conductive layer onthe second elongated plastic substrate having the second through-holeformed therein.

Here, the method of disposing the transparent conductive layer on theplastic substrate having a through-hole formed therein is notparticularly limited, and the material usable for the transparentconductive layer described in the plastic cell of the present inventionmay, for example, be disposed by a method such as coating, vapordeposition, or printing.

[Fluid Layer Disposing Step]

In the manufacturing method of the present invention, the fluid layerdisposing step is a step of disposing the fluid layer on the firsttransparent conductive layer.

Here, the method of disposing the fluid layer on the first transparentconductive layer is not particularly limited, and various known methodssuch as coating, dipping, and injection utilizing capillary phenomenoncan be used.

[Laminate Producing Step]

In the manufacturing method of the present invention, the laminateproducing step is a step of bonding the first plastic substrate, onwhich the first transparent conductive layer and the fluid layer aredisposed, and the second plastic substrate, on which the secondtransparent conductive layer is disposed, to each other by aroll-to-roll process, to produce an elongated laminate.

Here, the method of performing the bonding by a roll-to-roll process isnot particularly limited, and, for example, a method of passing thefirst plastic substrate, on which the first transparent conductive layerand the fluid layer are disposed, and the second plastic substrate, onwhich the second transparent conductive layer is disposed, between niprolls to achieve bonding, or the like can be used.

[Sealing Step]

In the manufacturing method of the present invention, the sealing stepis a step of performing a thermal fusion welding of the first plasticsubstrate and the second plastic substrate to each other, to seal thefluid layer in a longitudinal direction.

Here, the method of performing a thermal fusion welding is notparticularly limited as long as a method of giving energy required forthermal fusion welding to a plastic substrate is used. Specifically, amethod of bringing a high-temperature metal element into contact withthe plastic substrate, a method of concentrating a COx laser to theplastic substrate, a method of applying ultrasonic waves to the plasticsubstrate, and the like.

EXAMPLES

Hereinafter, the present invention will be specifically described withreference to examples. However, the materials, reagents, substanceamounts and proportions thereof, conditions, operations, and the likeshown in the following examples can be appropriately changed within ascope that does not depart from the gist of the present invention.Accordingly, a scope of the present invention is not limited to thefollowing examples.

Example 1

<Production of Transparent Conductive Layer>

A through-hole was formed in a polycarbonate (PC-2151, thickness 250 μm)manufactured by Teijin Limited using a hole punch. Then, a transparentconductive layer was produced with Ag nanowire by a method described inExample 1 of US2013/0341074A, and a laminate in which a plasticsubstrate formed of the polycarbonate and the transparent conductivelayer formed of Ag nanowire were laminated was produced. In the producedlaminate, a conductive material formed of Ag nanowire was also formed inthe through-hole provided in the polycarbonate.

<Production of Orientation Layer>

The laminate produced above was cut into 10 cm squares, and a polyamicacid orientation layer coating solution (JALS684, manufactured by JSRCorporation) as a liquid crystal orientating agent was coated thereonusing a bar coater #1.6. Thereafter, the resulting laminate was dried ata film surface temperature of 80° C. for 3 minutes to produce a liquidcrystal orientation layer 101. At this time, a film thickness of theliquid crystal orientation layer was 60 nm.

Two sets of laminates produced in this manner, in each of which theplastic substrate, the transparent conductive layer, and the liquidcrystal orientation layer were laminated in this order, were prepared.

<Production of Spacer Layer>

A spacer layer dispersion liquid was produced by using the followingformulation.

Formulation of Spacer Layer Dispersion Liquid

Bead spacer SP-208 (manufactured by 100 parts Sekisui Chemical Co.,Ltd.) by mass Methyl isobutyl ketone amount to give solid content of0.2%

The produced spacer layer dispersion liquid was coated on each of thetwo sets of the laminates, in which the liquid crystal orientation layerwas laminated, using an applicator with a clearance setting of 100 μm.

Thereafter, the laminate was heated so that a film surface temperaturethereof was 60° C., and dried for 1 minute to produce two sets oflaminates having a spacer layer.

<Production of Liquid Crystal Cell>

A liquid crystal layer composition was produced by using the followingformulation.

Liquid Crystal Layer Composition

ZLI 2806 (manufactured by Merck KGaA) 100 parts by mass Cholestericnonanate (manufactured by Tokyo 1.74 parts by mass Chemical IndustryCo., Ltd.) G-472 (manufactured by Hayashibara Co., Ltd.) 3.00 parts bymass

The produced liquid crystal layer composition was added dropwise on thecenter of one of two sets of the laminates having the spacer layerproduced as described above, and sandwiched with the other laminatehaving the spacer layer. Then, the liquid crystal layer composition wasuniformly spread by a roller to obtain a laminate containing the liquidcrystal layer composition.

Thereafter, the four sides of the present laminate were sealed bythermal fusion welding at 230° C. for 5 seconds using a heatingtemperature-control electric sealer (OPL-600-10, manufactured by FujiImpulse Co., Ltd.), and a plastic cell 001 having liquid crystalencapsulated therein was produced.

A sealing part of the plastic cell 001 manufactured as described abovewas sectionally cut using a microtome and checked with a field emissiontype scanning electron microscope (S-5200, manufactured by HitachiHigh-Technologies Corporation). As a result, as shown in FIG. 1, theplastic substrate 1 of the front surface (upper surface) and the plasticsubstrate 7 of the back surface (lower surface) were directly adhered toeach other to seal the fluid layer 4, and there was no transparentconductive layer between the two plastic substrates.

Regarding the plastic cell 001 manufactured as described above, in orderto check flexibility thereof, identification was made as to whetherthere was no problem in the sealing part even in a case of being bent by90° near the center.

<Checking of Drive>

An electrode was connected to each conductive material exposed on thefront surface (upper surface) and the back surface (lower surface) ofthe manufactured plastic cell 001, and a voltage of 3 V was applied tocheck whether the liquid crystal was capable of being driven toreversibly perform coloring and decoloring depending on application ornon-application of the voltage.

Comparative Example 1

A plastic cell 002 was manufactured in the same manner as in Example 1,except that in Example 1, for the sealing of the end portions, a UVsealing agent (TB 1220, manufactured by ThreeBond Holdings Co., Ltd.)was used instead of the thermal fusion welding and all four sides weresealed.

In order to check flexibility, the plastic cell 002 was bent by 90° nearthe center. As a result, the sealing agent was peeled off, and a part ofthe liquid crystal composition in the plastic cell flowed out.

Comparative Example 2

A plastic cell 003 was manufactured in the same manner as in Example 1except that a through-hole was not formed in the polycarbonate.

Attempts were made to install electrodes on the manufactured plasticcell 003. However, there was no conductive part and it was not possibleto drive the plastic cell 003.

EXPLANATION OF REFERENCES

-   -   1, 7: plastic substrate    -   2, 6: transparent conductive layer    -   3, 5: orientation layer    -   4: fluid layer    -   8, 10: conductive wire connected to electrode    -   9, 11: conductive paste    -   12, 13: through-hole    -   14: sealing part    -   100: plastic cell

What is claimed is:
 1. A plastic cell comprising: a first plasticsubstrate, a first transparent conductive layer, a fluid layer, a secondtransparent conductive layer, and a second plastic substrate, in thisorder, wherein the plastic cell further comprises a sealing part thatseals the fluid layer by deformation of a part of the first plasticsubstrate or the second plastic substrate, the first plastic substratehas a first through-hole, the second plastic substrate has a secondthrough-hole, the first through-hole has a first conductive materialtherein, and the second through-hole has a second conductive materialtherein.
 2. The plastic cell according to claim 1, wherein the firstconductive material is the same material as the first transparentconductive layer, and the second conductive material is the samematerial as the second transparent conductive layer.
 3. The plastic cellaccording to claim 1, wherein an orientation layer is provided betweenthe first transparent conductive layer and the fluid layer and betweenthe second transparent conductive layer and the fluid layer,respectively, and the fluid layer is a liquid crystal layer formed byusing a liquid crystal composition containing a liquid crystal compound.4. The plastic cell according to claim 2, wherein an orientation layeris provided between the first transparent conductive layer and the fluidlayer and between the second transparent conductive layer and the fluidlayer, respectively, and the fluid layer is a liquid crystal layerformed by using a liquid crystal composition containing a liquid crystalcompound.
 5. The plastic cell according to claim 1, wherein both thefirst plastic substrate and the second plastic substrate are elongatedfilms, and the plastic cell is in a roll form obtained by winding theelongated films in a longitudinal direction.
 6. The plastic cellaccording to claim 2, wherein both the first plastic substrate and thesecond plastic substrate are elongated films, and the plastic cell is ina roll form obtained by winding the elongated films in a longitudinaldirection.
 7. The plastic cell according to claim 3, wherein both thefirst plastic substrate and the second plastic substrate are elongatedfilms, and the plastic cell is in a roll form obtained by winding theelongated films in a longitudinal direction.
 8. The plastic cellaccording to claim 4, wherein both the first plastic substrate and thesecond plastic substrate are elongated films, and the plastic cell is ina roll form obtained by winding the elongated films in a longitudinaldirection.
 9. The plastic cell according to claim 1, further comprisingan electrode, wherein the electrode is connected to at least one of thefirst transparent conductive layer or the second transparent conductivelayer via the conductive material.
 10. The plastic cell according toclaim 2, further comprising an electrode, wherein the electrode isconnected to at least one of the first transparent conductive layer orthe second transparent conductive layer via the conductive material. 11.The plastic cell according to claim 3, further comprising an electrode,wherein the electrode is connected to at least one of the firsttransparent conductive layer or the second transparent conductive layervia the conductive material.
 12. The plastic cell according to claim 4,further comprising an electrode, wherein the electrode is connected toat least one of the first transparent conductive layer or the secondtransparent conductive layer via the conductive material.
 13. Theplastic cell according to claim 5, further comprising an electrode,wherein the electrode is connected to at least one of the firsttransparent conductive layer or the second transparent conductive layervia the conductive material.
 14. The plastic cell according to claim 6,further comprising an electrode, wherein the electrode is connected toat least one of the first transparent conductive layer or the secondtransparent conductive layer via the conductive material.
 15. Theplastic cell according to claim 7, further comprising an electrode,wherein the electrode is connected to at least one of the firsttransparent conductive layer or the second transparent conductive layervia the conductive material.
 16. The plastic cell according to claim 8,further comprising an electrode, wherein the electrode is connected toat least one of the first transparent conductive layer or the secondtransparent conductive layer via the conductive material.
 17. A methodfor manufacturing a plastic cell, comprising: a step of forming a firstthrough-hole in a first elongated plastic substrate, a step of disposinga first transparent conductive layer on the first elongated plasticsubstrate having the first through-hole formed therein; a step offorming a second through-hole in a second elongated plastic substrate, astep of disposing a second transparent conductive layer on the secondelongated plastic substrate having the second through-hole formedtherein; a step of disposing a fluid layer on the first transparentconductive layer; a step of bonding the first plastic substrate, inwhich the fluid layer is disposed on the first transparent conductivelayer, and the second plastic substrate, on which the second transparentconductive layer is disposed, to each other by a roll-to-roll process,to produce an elongated laminate; subsequent to production of thelaminate, a step of performing a thermal fusion welding of the firstplastic substrate and the second plastic substrate to each other, toseal the fluid layer in the longitudinal direction; and a step ofwinding the laminate in a roll shape.